Steam-engine.



No. 67!,628. Patented Apr. 9, mm.

W. w. LEWIS, Decd,

K. LEWIS, Administratrix.

STEAM ENGINE.

(Application filed Jan. 5, 1901.)

(lo Iodel.) 4 Sheets-Sheet I.

405171 e 5366. [700g nib? No. 671,628. Patented Apr. 9, NM.

W. W. LEWIS, Becd.

' K. LEWISv Administrairix.

STEAM ENGINE.

(Application filed. Jan. 5, 1901.) N (No Model.) 4 Sheets-Sheet 2.

ill" No. mp2s. Patanted Apr. 9, ISM. w. w. LEWIS, um.

4 Sheets-sheaf 4.

(No Model.)

witnesses.

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UNITED STATES PATENT OFFICE.

KATHERINE LEWIS, OF CINCINNATI, OHIO, ADMINISTRATRIX OF WILLIAM W. LEWIS, DECEASED, ASSIGNOR TO EUGENE L. LEWIS, TRUSTEE, OF

SAME PLACE.

STEAM-ENGIN E.

SPECIFICATION forming part of Letters Patent N 0. 671,628, dated April 9, 1901.

Application filed January 1901. Serial No. 42,221. (No model.)

To an whom it may concern-.-

Be it known that WVILLIAM W. LEWIs,late a citizen of the United States residing at Hyde Park, in the county of Hamilton and State of 5 Ohio, did invent certain new and useful Improvements in Steam-Engines, of which the following is a full, clear, and exact description,reference being had to the accompanying drawings, forming part of this specification.

This invention relates to steam-engines employing slide-valves, whether for marine, stationary, or locomotive engines, and especially to that class of engines, single or compound, which use the ordinary link which is in general use in all railroad service for the double purpose of varying the cut-off and reversing. The object of the invention is to provide novel practical means which, without increased vibration of the rocker-arm, will give increased longitudinal play to the valve-rod to secure quick induction of live steam as Well as acorresponding quickeduction of the steam after it has performed its work within the cylinder, so as to reduce the amount of compression to a point that will not obstruct the full development of power, and thereby obtain both economy in the use of steam and in the fuel necessary to produce it and also to produce accelerated speed of the engine.

0 3 rocker-arm having a bearing-surface cooperating with hearing projections on the valverod, which bearing-surfaces of the rocker-arm on opposite sides are so shaped as to im- 5 part both greater and quicker lineal movement to the valve on the opening sides of the ports for quick induction on one side and full and complete exhaust on the other side.

It also consists in certain preferred features of construction and adjustment whereby the results hereinafter stated are best accomplished.

The novelty of the invention will be hereinafter more fully set forth, and specifically 5 pointed out in the claims.

In'the-accompanying drawings, Figure 1, Sheet 1, is a side elevation of an engine-valve mechanism, partly in section and partly broken away and illustrating the invention, the view being taken from a point between the wheels and looking outward. Fig. 2,Sheet 1, is a partial sectional central side elevation To this end the invention consists in a of a cylinder, steam-chest, and slide-valve of the ordinary type and movement. Fig. 3, Sheet 2, is an enlarged side elevation, partly broken, of the improvedrocker-arm, repre* senting the same different positions and of one-third actual size for locomotive-work. Fig. 4., Sheet 2, is a sectional side elevation, partly broken, of a valve of the Allen type arranged in relation to the rocker-arm of Fig. 3, so that the relative positions of the two may be considered together. Fig. 5, Sheet 2, is a side elevation, diminished, of a modified form of the upper part of a rocker-arm embodying the invention and also showing its connection with the valve-rod. Fig. 6, Sheet 3, is a broken side elevation, partly in section, of the valve and rocker-arm with their respective parts, the valve being of the Allen typeand the rocker-arm being shown in vertical position. Fig. 7, Sheet 3, is an enlarged plan view, one-third size, of the yoke inserted in the valve-rod and carrying the bearingrollers which are confined in the slots of the upper part of the rocker-arm which passes through the opening in the yoke. Sheet 3, is atransverse section on the dotted line w an of Fig. 7 looking to the right. Fig. 9, Sheet 3, is an enlarged side elevation of the outer bearing of the valve-rod illustrated in Fig. 6. Fig. 10, Sheet 3, is an end elevation of Fig. 9 looking to the left. Fig. 11, Sheet 3, is a diminished detail, in side elevation, of the parts making up the bearing of Fig. 9 disconnected from each other. Fig. 12, Sheet 4, is a diagrammatic view, in side elevation, of the present rocker-arm and that of a former rocker arm in corresponding relations of movement, both in solid and dotted lines, to illustrate the increased travel of the valverod and Valve of the present rocker-arm over that of the old rocker-arm when both are vibrated from the center to exactly the same distance.

The same lettersof reference are used to indicate identical parts in all the figures.

I-Ieretofore most rocker-armsof a link-movement gave a uniform motion to the valve, or at most accelerated the movement at midtravel of the valve, which so far has proved of no practical benefit.

This invention provides a new and useful method for the purpose of an economical as Fig. 8,

, ically considered is really the starting-point well as a more efiective distribution of steam and may be practically applied to either stationary, marine, or locomotive engines, but more especially locomotives, whether they be single or compound, whereby a larger development of both power and speed are obtained within shorter points of cut-off than is possible at the same points of cut-off applied to the ordinary valve-movement.

The principal reasons why the ordinary valve-movement is well known to be most dofective, especially at short points of cut-off, are at least twofoldnamely, an overamount of lead, especially at the center notch, for preadmission of steam before the piston reaches the end of the stroke, as well as a deficiency in the release of spent steam before the piston moves on its return stroke, which is no other than a loss of useful power and a development of negative power. The abovenamed defects are remedied by the improved valve-movement, no unequal setting of the forward eccentric from that of the backing eccentric being necessary, such as is resorted to by some for the purpose of reducing the excessive lead in the working notch of the ordinary valve-movement. Nor does this improved movement require any abortive and wasteful appliance as that which is technically known as inside clearance in order to give a more timely and somewhat-larger release, which is often resorted to in the use of the common movement, even in single engines, but more particularly so in those that are compound. The above well-known defects of the ordinary valve-movement are entirely removed in the operation of my device, and in order to present reliable proof of the difference between the ordinary valvemovement as compared with this improved movement it is said that the Chespeake and Ohio Railroad Company by their assistant master mechanic of the western division took all the points of the valve-movement of two similar engines known as Nos. 46 and 47, the engine No. 46 being equipped with the ordinary valvemovement, while the engine No. 4.7 has this improved valve-movement, both of which are herewith submitted in tabular form for the convenience of comparison. However, in advance of reference to the drawings it is said that the reason why this invention overcomes the defective points of the ordinary valvemovement is owing to the peculiar construction of the upper arm of the rocker, which will be more particularly described later on,

.and at present it is merely stated that the central point of its movement when mechanof its oscillation. It radically differs from the ordinary movement because it imparts a greater movement to both valve rod and valve at the starting-point of its oscillation than it does when farther removed from the above-given point. This is shown in the table which will be hereinafter given and which shows that the engine No. 47, with the reverse-lever hooked in the center notch, imparted a movement at that point which instead of being cramped in the exhaust, as the ordinary movement must be, it moved the valve from its mid-travel point one-eighth of an inch beyond a full port-opening for the exhaust. Consequently the center notch of this device instead of being a nominal center from which no useful work can be obtained, which is the case with the ordinary movement, produced a workable engine. This device shows not only a free and easy movement when operated in the center notch, but also develops power in proportion to the amount of steam admitted, and of course the same principle of development of increased power will be obtained within all the other points of cut-off, whereby all the useful power is obtained within shorter points of cut-olf than is possible to be obtained by the ordinary movement. Therefore inasmuch as this improved upper rocker-arm may be made to impart to the valve, even when the reverselever is hooked in the center notch, more than a full opening of port for the exhaust, it will be obvious that the difference of movement as compared with the ordinary move-.

ment requires greater length for the outside lap of the valve, so as to avoid the untimely preadmission of steam which would otherwise occur to such an extent before the piston would terminate its stroke as to be of course inoperative, and yet while the outside of the valve will be about one-inch longer the exhaust-cavity is the same as that used in the ordinary valve, and the large movement of the valve accounts for the large difierence of exhaust.

As already stated in part, the improved distribution of steam is owing to the mechanical features of the hearings in the upper rocker-arm, with which the valve-rod is connected, and by referring to the drawings or comparing-table it will be found that at the central point of oscillation it will impart a lineal movement to the valve-rod one-third greater than the oscillating movement of the rocker. This is the result of finding the required proportion of convergence for the positive as well as divergence on the negative sides of the oscillations of the rocker-arm bearings, which in their connection with the valve-rod will be in constant and unvarying bearings at all points of valve travel. However, the convergence of the hearings in the rocker-arm must be designed so as not only to perform the functions which have been already referred to--namely, the induction as well asthe eduction of steambut also the continuous rotary movement of the rollers in one direction. As applied to the induction it will be found that the relative convergence of the rocker-arm bearings, as shown by the drawings and comparing-table, does entirely remove the ordinary discrepancy between the full and mid-gear lead.

Now, referring to the drawings, in Fig. 1, A

IIO

rocker-arm J in its preferred form is best illustrated in Figs. 1, 3, and 6, where it is shown asa single steel casting with an upper projection containing through it a'slot of peculiar formation. The manner of laying out this slot is best illustrated in Fig. 6, where K is a yoke interposed in and forming part of the valve-rod, whose adjacent and rear portions are rigidly secured to collars b on the extremities of the yoke. The yoke has through it from top to bottom a rectangular aperture 0, in which are journaled on the axis of the valverod two rollers L and L, and these rollers areconfined in the slot M of the rocker-arin before referred to, the upper part of which rocker-arm passes through the aperture 0 in the yoke. In the illustration given the valve D has a length on its bearing-face of nine and three-eighths inches, and the rollers L L are exactly nine inches between centers and confined in the slotM of the rocker-arm, the width of which slot is just sufficient to accommodate the diameter of the rollers so as to give them play without binding. Now, returning to the manner of laying out the slot M on each upper projecting end of the rocker-arm, first assume a radial line at from the axis 6 of the rockerarm when the rocker-arm is perpendicular, and on this radial line, which is likewise perpendicular, strike an arcf from the center e, the radius of which are is eleven and sevensixteenths inches. Then assume two other lines g h from the center 6 and forming radii of the arc and whose acute angle at the center 6 with the vertical line d is each thirteen and one-half degrees. The points of juncture of the radii g h with the arcf form the centers from which the bearing-curves kl of the slot M are struck on each side. The top ends of the slots are rounded, as shown, for neatness of appearance, and in order to lighten the rocker-arm their convergent lower ends may be united, forming one continuous slot Mwith two convergent bearing-surfaces, in which the rollers L L are secured. For neatness of appearance the upper ends of the rocker-arms, on their upper andlower sides, follow the contour of the slot M. The effective upper end of the rocker-arm will be a line through the axis of the valve-rod, and the distance of this axial line from the center 6 of the rocker-arm is, in the illustration given, nine and threequarters inches.

For the purposes of ordinary locomotivework it has been found from actual experience that the above proportions give the results at which this invention is aimed and are perfeotly safe to follow. In other cases, where the valve is shorter or longer, the same proportions 'may be employed both as to the distance between the centers of the rollers and the length of the are from which the centers are found in laying out the curves to form the operating-bearings in the slot of the rocker-arm.

In Fig. 5 is shown a modified form of rockerarm embodying this invention, but made up of separate pieces for purposes of adjustment and taking up wear; but this arm also follows the rules described with reference to the arm in Fig; 6, and here it will be observed that the lower or connecting part of the slot M is dispensed with and only the bearing portions on the opposite sides which engage the rollers are retained.

In Fig. 1 is shown a type of valve somewhat similar to the ordinary valve, but of a length equal to that of the valve shown in Fig. 6, covering the inlet-ports n o and the exhaustport 19, and the rocker-arm is shown as thrown slightly in advance, so as to fully uncover the port at to the exhaust and slightly open the inlet-port 0, while in Fig. 2 the ordinary type of valve, which is about one inch shorter than that of Fig. 1, is represented as being coupled to the ordinary form of rocker-arm, which occupies the same position as the rockerarm of Fig. 1. It will be observed from these two figures that while the pistons are both in the same position the positions of the valves are not the same, the valve in Fig. 1 showing atrifle more than a full exhaust-opening. It shows just enough steam-opening to form an eifective cushion to prevent the sudden reversing of the motion of the piston from causing a jar to the engine, while the valve in Fig. 2 instead of showing a full exhaust-port shows but a trifle more than half a full exhaust-port, and the steam-port instead of forming an eifective cushion for the piston to prevent the jar or jolt is open to such an extent that it would producea negative power in the cylinder which would very materially diminish the power and speed of the engine.

Now, referring to Fig. 4:, where a valve of the Allen type is shown in connection with this improved rocker-arm, its operation with that of the ordinary rocker-arm is compared, as follows: In said figure the rocker-arm is advanced from its perpendicular position the distance between the points a b on the dotted line indicated which is coincident with the axis of the valve-rod, and this movement of the rocker has carried the rollers a greater distance, approximately one-third, as indicated by the distance between the centers of the rollers shown in dotted lines and the centers of those shown in solid lines. This movement of the rocker-arm will have carried the valve shown in Fig. 4 from a position indicated by the dotted line o to the position shown by the solid lines, where it will be no- IIO ission th the 55 I This diflerence and the rethere is a considerable gain, as indicated by the dotted line 72/, connecting the two vertical and that by the use of this present form of rocker-arm, with the acting parts of its slots ing therefrom,it is possible to obtain a quicker in either direction, and thus obtain a quicker and complete exhaust before the adm is of steam to the opposite end of the cylinder, 5

gine is obtained which could not heretofore struction, and which efficiency is increased 50 by the movement of the lever a to any notch ing the operation of engine No. 46 w old form of rocker-arm and the second table The ing that and larger throw of the valve from mid-travel ic view,

. Lewis, the present be obtained at mid-gear by any previous con- The dotted lines show tables which follow, the first table represent- With this representing engine No. 47 equipped with the Engine No. 46.

(1 both in the crossoverbtaine opening 1s 0 ticed that more than a full exhaust-port is be seen that with this present construction 0 obtained and that a very suflicient steamwould fail of opening by the distance shown dotted line extending from the centers of the 3 5 from the position of the valve shown in the two lower rollers in their changed positions, dotted line d to the edge e of the port 0.

port would be opened to such an extent that arm and the upper parts of said slots diverg- 40 it would be impossible-to run the engine. arrow f indicates the amount of open In Fig. 12, which is a diagram mat compared the gain of valve-movement of the and thereby at the central notch or mid-gear present rocker-arm with the same extent of of thereversing-lever an efliciency of the enrocker-arm movement of a former patent 2o taken out by William W ,128, dated December 5, 1893, the upper figure representing the present rocker-arm and from the center.

port and in the direct port, while if the same lines from the centers of the upper rollers 5 valve were applied to the ordinary movement over the dotted line i connecting the vertical However, if the ordinary length were applied 10 to the present improved rocker-arm the steamconverging toward the center of the rockerthe ordinary valve would have as applied to a I 5 the present improved rocker-arm.

inventor, jointly with J eptha Garrard, No. 510

the lower figure representing the Garrard and sults obtained are clearly illustrated by the 25 Lewis construction.

both rocker-arms vertical and the solid lines their forward throw toexactly the same extent, as indicated by the arrows g. equal throw of both the rocker-arms it will present invention.

It will be seen from the foregoing tables that not only is a greater power obtained at the center notch (represented by 1 in the left column of each table) than is obtained by the ordinary rocker-arm, but for each notch in advance of the center this power is greatly augmented over that of the ordinary rockerarm, for from mid-travel each way the valve is given a quick movement and a longer movement than the ordinary valve, so that a quick and complete exhaust is obtained on the one side before the induction sufficient for cushioning occurs on the opposite side.

Now, referring to Figs. 7, 8, 9, 10, and 11, the'details of construction of the roller-bearings and the support for the rear end of the valve-rod will be described. As seen in Figs. 7 and 8,'there is a plug M passed through taper apertures in the side walls of the yoke K for each of the rollers L L, which fit snugly between the side walls of the yoke, and the rollers bear on them. The outer ends of these plugs are threaded to receive fastening-nuts N, and into the larger end of each plug is a central bore 0, into which is fitted the end of an oil-cup P, which discharges its lubricant through a channel a from the bore 0 into the bearings of the rollers. The bearing for the rear end of the valve-rod is composed of a central sleeve Q, on the ends of which are first fitted rings R, having lower threaded stems which pass through apertures in a flange S of a bracket T, suitably secured to the framework of the engine. These stems h are held in place by nuts 0, and outer rings U are finally screwed on the threaded ends of the sleeve Q. This construction forms a very secure and at the same time adjustable bearing for the rear end of the valve-rod which passes through it. Oilcups d and e are provided for the valve-rod bearing and the upper ends of the slots in the rocker-arm, respectively, for purposes of lubrication, as will be readily understood.

Having thus fully described the invention, what is claimed is- 1. The combination of a Valve and its rod having actuating-bearings, of a rocker-arm having curved bearing-surfaces on opposite sides constantly engaging the bearings, said curved bearing-surfaces converging at their inner ends toward the axis of the rocker-arm and diverging therefrom at their outer ends, whereby after mid-travel in either direction a quicker and increased movement is imparted to the valve, substantially as described.

2. In the valve-gear of an engine, the combination of a slide-valve for the cylinder, a valve-rod connected to the slide-valve and having bearings carried thereby, a rockerarm having on opposite sides thereof curved slots engaging said bearings, said slots converging at their inner ends toward the axis of the rocker-arm and diverging therefrom at their outer ends, a lower extension of said rocker-arm, link gearing actuated by a lever and eccentrics on the piston-driven shaft connected to said link gearing, whereby the throw of the valve may be varied at will, substantially as described.

3. The combination of a valve and its rod having actuating bearing-rollers, of a rockerarm having curved bearing-s11 rfaces on opposite sides constantly engaging' the bearingrollers, said curved bearing-surfaces converging at their inner ends toward the axis of the rocker-arm and diverging therefrom at their outer ends, whereby after mid-travel in either direction a quicker and increased movement is imparted to the valve, substantially as described. Y

4. In the valve-gear of an engine, the combination of a slide-valve for the cylinder, a valve-rod connected to the slide-valve and having roller bearings carried thereby, a rocker-arm having on opposite sides thereof curved slots engaging said rollers, said slots converging at their inner ends toward the axis of the rocker-arm and diverging therefrom at their outer ends, a lower extension of said rocker-arm, link gearing actuated by a lever and eccentrics on the piston-driven shaft connected to said link gearing, whereby the throw of the valve may be varied at will, substantially as described.

5. In the valve-gear of an engine, the combination of a slide-valve for the cylinder, a valve-rod connected to the slide-valve, a yoke in said valve-rod having roller-bearings carried therein, a rocker-arm, the upper end of which extends through said yoke having on opposite sides thereof curved slots engaging said rollers, said slots converging at their inner ends toward the axis of the rocker-arm and diverging therefrom at their outer ends, a lower extension of said rocker-arm, link gearing actuated by a lever and eccentrics on the piston-driven shaft connected to said link gearing, whereby the throw of the valve may be varied at will, substantially as described.

6. In valve-gear of the character described, the combination of the yoke K with vertical apertures c therethrough, the rollers L L journaled in said yoke, the rocker-arm J having its slotted upper end extending through the yoke with the rollers L L confined and bearing in the slots of the rocker-arm, substantially as described.

7. In valve-gear of the character described, the combination of the yoke K with vertical apertures c therethrough, the rollers L L journaled on bearings through said yoke hav- IIS ing tapering seats therefor and held by nuts KATHERINE LEWIS, Admtm'stratriac 0f the estate of Wm. T V. Lewis,

deceased.

Witnesses:

OWEN N. KENNEY, WM. J. Rick. 

